Used $ at the beginning of the game, to gain on those who started before me, not allot though, bought some research in the end of chapter 1 or at the start of chapter 2, dont recall witch it was, also bought 5 builders almost right away, and some culture buildings, but again not allot of those either, had 1 shrine, 1 protector, 2 seasnakes, they are all gone and now i have 4 elder dragons, i never bought or build any culture buildings that has workers, i went with houses all the way.
So my KP came mostly from provinces, and from coins, loads of players just go for the coins they "need" and stop making them when they have enough, but they are very useful for buying KP, and by the time my workshops where done (lvl 15) i went down to 100% culture bonus, and kept it there, it gives space for more houses, and more factories. Culture bonus only helps houses and workshops, so it´s not a big deal, when you have loads of houses and workshops.
oh and playing all day helps too
